Recently, a recording medium, such as a CD and a DVD, which allows data recording and data reproduction by using a digital signal has been spread. Along with that, an information reproducing apparatus, which performs a unique reproduction process due to the digital signal, is also under development.
For example, in a CD and a DVD, a plurality of music pieces (i.e. content data) are recorded in association with each other. More specifically, for example, music pieces, each having a predetermined reproduction time length, are recorded as a plurality of data groups distinguished by track numbers. Thus, a DJ player can perform cue-reproduction which searches for a head address of each music piece and reproduces it, random-reproduction which arbitrarily changes the reproduction order of each music pieces, or the like. Moreover, it is also possible to change the volume of a piece of music to be reproduced, and to change its tempo. Recently, a DJ player which allows not only music but also video images to be reproduced in the same manner has appeared.
Moreover, by using a mixer, it is possible to mix music pieces or the like, which are reproduced from a plurality of DJ players. For example, it is assumed that when a piece of music reproduced by one DJ player comes from a speaker, another piece of music reproduced by another DJ player is mixed therewith. In this case, for example, by increasing the volume of the piece of music reproduced by the another DJ player while reducing the volume of the piece of music reproduced by the one DJ player, it is possible to continue the music reproduction, with the two different pieces of music smoothly connected.
Moreover, by using an effecter, it is possible to add various effects, to the music to be reproduced or the like. Depending on the effecter, it is possible to generate a delay sound, to generate an echo sound, to send a sound between right side and left side, to add the effect that a jet plane ascends or descends periodically, or to cut a sound periodically.
These are used to provide a user with more comfortable music or music with a sensation of reality. On the other hand, as a method of providing the comfortable music or the music with a sensation of reality, a method disclosed in a patent document 1 is listed    Patent document 1: Japanese Patent Application Laid Open NO. 2002-207488